Send toolbar button click events

android/app/src/main/java/com/reactnativenavigation/activities/BaseReactActivity.java

 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.Menu;
+import android.view.MenuItem;
 import android.widget.EditText;
 import android.widget.Toast;
 
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.ReactRootView;
+import com.facebook.react.bridge.Arguments;
+import com.facebook.react.bridge.WritableMap;
 import com.facebook.react.common.ReactConstants;
 import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
 import com.facebook.react.shell.MainReactPackage;
 import com.reactnativenavigation.BuildConfig;
 import com.reactnativenavigation.core.RctManager;
+import com.reactnativenavigation.core.objects.Button;
 import com.reactnativenavigation.core.objects.Screen;
 import com.reactnativenavigation.packages.RnnPackage;
 import com.reactnativenavigation.utils.ContextProvider;
     private static final String TAG = "BaseReactActivity";
     private static final String REDBOX_PERMISSION_MESSAGE =
             "Overlay permissions needs to be granted in order for react native apps to run in dev mode";
+    private static final String EVENT_TOOLBAR_BUTTON_CLICKED = "OnToolbarButtonClicked";
 
     @Nullable
     protected ReactInstanceManager mReactInstanceManager;
         return null;
     }
 
-    public abstract String getCurrentNavigatorId();
+    protected abstract String getCurrentNavigatorId();
+
+    protected abstract Screen getCurrentScreen();
 
     public abstract int getScreenStackSize();
 
         return super.onCreateOptionsMenu(menu);
     }
 
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (item.getItemId() == android.R.id.home) {
+            onBackPressed();
+        } else {
+            String eventId = Button.getButtonEventId(item);
+            assert eventId != null;
+
+            WritableMap params = Arguments.createMap();
+            RctManager.getInstance().sendEvent(eventId, getCurrentScreen(), params);
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
     public Menu getMenu() {
         return mMenu;
     }

android/app/src/main/java/com/reactnativenavigation/activities/RootActivity.java

      // No need to implement stack interface since this activity is only used to start other
     // activities such as TabActivity or SingleScreenActivity.
     @Override
-    public void push(Screen screen) {
-    }
-
-    @Override
-    public Screen pop(String navigatorId) {
+    protected Screen getCurrentScreen() {
         return null;
     }
 

android/app/src/main/java/com/reactnativenavigation/activities/SingleScreenActivity.java

         return mNavigatorId;
     }
 
+    @Override
+    protected Screen getCurrentScreen() {
+        return mScreenStack.peek();
+    }
+
     @Override
     public int getScreenStackSize() {
         return mScreenStack.getStackSize();

android/app/src/main/java/com/reactnativenavigation/activities/TabActivity.java

 
     private TabLayout mTabLayout;
     private ViewPager mViewPager;
-
-    private ArrayList<Screen> mScreens;
     private ViewPagerAdapter mAdapter;
 
     @Override
         mTabLayout = (TabLayout) findViewById(R.id.tabLayout);
         mViewPager = (ViewPager) findViewById(R.id.viewPager);
 
-        mScreens = (ArrayList<Screen>) getIntent().getSerializableExtra(EXTRA_SCREENS);
+        ArrayList<Screen> screens = (ArrayList<Screen>) getIntent().getSerializableExtra(EXTRA_SCREENS);
 
-        setupToolbar();
-        setupViewPager();
+        setupToolbar(screens);
+        setupViewPager(screens);
     }
 
-    private void setupToolbar() {
+    private void setupToolbar(ArrayList<Screen> screens) {
         setSupportActionBar(mToolbar);
-        mToolbar.setScreens(mScreens);
+        mToolbar.setScreens(screens);
     }
 
-    private void setupViewPager() {
-        mAdapter = new ViewPagerAdapter(this, mViewPager, mToolbar, mScreens);
+    private void setupViewPager(ArrayList<Screen> screens) {
+        mAdapter = new ViewPagerAdapter(this, mViewPager, mToolbar, screens);
         mViewPager.setAdapter(mAdapter);
         mTabLayout.setupWithViewPager(mViewPager);
         mTabLayout.setOnTabSelectedListener(mAdapter);
     }
 
     @Override
-    public String getCurrentNavigatorId() {
+    protected Screen getCurrentScreen() {
+        return mAdapter.peek(getCurrentNavigatorId());
+    }
+
+    @Override
+    protected String getCurrentNavigatorId() {
         return mAdapter.getNavigatorId(mViewPager.getCurrentItem());
     }
 

android/app/src/main/java/com/reactnativenavigation/adapters/ViewPagerAdapter.java

         return stack != null ? stack.pop() : null;
     }
 
+    public Screen peek(String navigatorId) {
+        ScreenStack stack = mStackByNavigatorId.get(navigatorId);
+        return stack != null ? stack.peek() : null;
+    }
+
     @Override
     public Object instantiateItem(ViewGroup container, int position) {
         ScreenStack view = mScreenStacks.get(position);
         // Send tab selected event
         WritableMap params = Arguments.createMap();
         Screen screen = mScreenStacks.get(position).peek();
-        params.putString(Screen.KEY_NAVIGATOR_EVENT_ID, screen.navigatorEventId);
-        RctManager.getInstance().sendEvent(EVENT_ON_TAB_SELECTED, screen.navigatorEventId, params);
+        RctManager.getInstance().sendEvent(EVENT_ON_TAB_SELECTED, screen, params);
     }
 
     @Override

android/app/src/main/java/com/reactnativenavigation/core/RctManager.java

 import com.facebook.react.bridge.ReactContext;
 import com.facebook.react.bridge.ReactContextBaseJavaModule;
 import com.facebook.react.bridge.WritableMap;
+import com.reactnativenavigation.core.objects.Screen;
 
 import java.util.List;
 
      * Sends an event to JavaScript using <a href="https://facebook.github.io/react-native/docs/native-modules-android.html#sending-events-to-javascript">RCTDeviceEventEmitter</a>
      * @param eventName Name of the event
      * @param params Event params
-     * @param navigatorEventId Id of the navigator
+     * @param screen screen which should receive the event
      */
-    public void sendEvent(String eventName, String navigatorEventId, WritableMap params) {
+    public void sendEvent(String eventName, Screen screen, WritableMap params) {
         RCTDeviceEventEmitter eventEmitter = getEventEmitter();
         if (eventEmitter == null) {
             return;
         }
 
         params.putString(KEY_EVENT_ID, eventName);
-        eventEmitter.emit(navigatorEventId, params);
+        params.putString(Screen.KEY_NAVIGATOR_EVENT_ID, screen.navigatorEventId);
+        eventEmitter.emit(screen.navigatorEventId, params);
     }
 
     private RCTDeviceEventEmitter getEventEmitter() {

android/app/src/main/java/com/reactnativenavigation/core/objects/Button.java

 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
+import android.view.MenuItem;
 
 import com.facebook.react.bridge.ReadableMap;
 import com.reactnativenavigation.BuildConfig;
         sStringToNumericId.put(id, itemId);
         return itemId;
     }
+
+    /**
+     * Each button has a string id, defined in JS, which is used to identify the button when
+     * handling events.
+     * @param item Toolbar button
+     * @return Returns the event id associated with the given menu item
+     */
+    public static String getButtonEventId(MenuItem item) {
+        for (Map.Entry<String, Integer> entry : sStringToNumericId.entrySet()) {
+            if (entry.getValue() == item.getItemId()) {
+                return entry.getKey();
+            }
+        }
+
+        return null;
+    }
 }

android/app/src/main/res/layout/toolbar.xml

-<?xml version="1.0" encoding="utf-8"?>
-<app:android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
-    android:id="@+id/toolbar"
-    android:layout_width="match_parent"
-    android:layout_height="?attr/actionBarSize"
-    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
-    app:layout_collapseMode="pin"/>